Drilling operations have become increasingly expensive as the need to drill deeper, in harsher environments, and through more difficult materials have become reality. Additionally, testing and evaluation of completed and partially finished wellbores has become commonplace, such as to increase well production and return on investment.
In working with deeper and more complex wellbores, it becomes more likely that tools, tool strings, and/or other downhole apparatus may become stuck within the wellbore. In addition to the potential to damage equipment in trying to retrieve it, the construction and/or operation of the well must generally stop while tools are fished from the wellbore. The fishing operations themselves may also damage the wellbore and/or the downhole apparatus.
Furthermore, downhole tools used in fishing operations are regularly subjected to high temperatures, temperature changes, high pressures, and the other rigors of the downhole environment. Consequently, internal components of the downhole tools may be subjected to repeated stresses that may compromise reliability. One such downhole tool, referred to as a jar, may be used to dislodge a downhole apparatus when it becomes stuck within a wellbore. The jar is positioned in the tool string and/or otherwise deployed downhole to free the downhole apparatus. Tension load is applied to the tool string to trigger the jar, thus delivering an impact intended to dislodge the stuck downhole apparatus.